An inductor apparatus is used in a power-supply circuit and the like.
Related art is discussed in Japanese Laid-open Patent Publication No. 10-233469, Japanese Laid-open Patent Publication No. 2008-21996, Japanese Laid-open Patent Publication No. 2005-150490, Japanese National Publication of International Patent Application No. 2008-537355, or International Publication Pamphlet No. WO 2007/129526.